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T O P I C R E V I E W

LM-12

How will all the planned Soyuz and International Space Station (ISS) crew assignments change if the STS-135 crew cannot return to Earth onboard Atlantis? What would that schedule look like?

There must be a pre-launch plan in place with alternate crew assignments to deal with that possibility, however remote it might be.

Robert Pearlman

Per NASA:

Rex Walheim would remain on the station for 70 days and land with Soyuz TMA-21 (26S) in September 2011.

Chris Ferguson would stay on ISS for 131 days and return with Soyuz TMA-02M (27S) in November 2011.

Sandy Magnus would be on station for 273 days and land on Soyuz TMA-03M (29S) in April 2012.

Doug Hurley would stay on ISS for 335 days, landing on Soyuz TMA-04M (30S) in June 2012.

As a result of this schedule, Mike Fossum's stay on the station would be extended to more than 300 days and Ron Garan would be onboard for over 250 days.

NASA and Roscosmos have not yet decided who will launch on each Soyuz in such a situation, but it would only be two people, leaving the third seat empty for the returning crew member.

LM-12

So I guess that means there will be four Russian Sokol spacesuits onboard STS-135 when it launches. Is that correct?

Robert Pearlman

The STS-135 crew's Sokol suits will be launched on an as-needed basis with Soyuz (I believe, and can double check, but the suits won't even be made until after a "safe haven" scenario has been declared).

Correction: All four Sokol suits and custom-fitted Soyuz seat liners have already been produced. Walheim's suit and liner is flying on Atlantis in the Raffaello MPLM. The others will be launched sequentially on Russian Progress supply ships.

Tom

Very interesting.

Though highly unlikely, how was it determined which Atlantis crew member remained onboard the longest?

Robert Pearlman

The order was dictated by the crew members' skill sets. From Doug Hurley's NASA pre-flight interview:

Sandy and I would be the last two and it's because we've got the robotics in the mix as well as EVA and, because you essentially become a de facto member of the space station crew because if this rescue was declared they're not going to fly people up in that empty seat because they need it for us to come down, so we have to assume at least some sort of a role as a crew member on space station. So that's the way they've sorted it out.

Incidentally, were this to happen, there's a good possibility that Hurley would delay his wife's (Karen Nyberg) own stay on the station.

Skylon

Interesting. But for Chris Ferguson it must sort of fly in the face of what he knows as an officer. As the Commander of STS-135, you'd think his instinct would be to be the last one down, once his crew is safe. But the logic makes sense. They would become defacto ISS crew members.

In any case, I'm not following the trickle down. Is Soyuz TMA-22 going to fly with the same crew? Or minus Dan Burbank? It sounds like the logic becomes with six US astronauts up there, basically no American is going to launch on a Soyuz until the last two are primed to come down (so Soyuz TMA-05M). Ultimately resulting in every US ISS crew member being bumped four seats downstream.

LM-12

Could the Russians launch a Soyuz spacecraft with one cosmonaut and return with a crew of three? It would be interesting to see how the Soyuz up/down crew selection would play out.

Tom

quote:Originally posted by LM-12:Could the Russians launch a Soyuz spacecraft with one cosmonaut and return with a crew of three?

Soyuz 4 has.

LM-12

That involved a rendezvous in space between Soyuz 4 and Soyuz 5. They did not dock. I don't know if that would make a difference.

That Soyuz 5/4 EVA crew transfer was pretty impressive though for 1969.

Robert Pearlman

Although upgrades to the Soyuz TMA/TMA-M series were said to enable just one crew member to fly the spacecraft, current rules require two trained crew members aboard.

According to NASA, the Soyuz CSCS crew compliment hasn't been finalized (beyond the returning STS-135 crew members), but the prior assigned crews (even the Russian cosmonauts) would not necessary fly on the Soyuz that they were previously assigned.

LM-12

quote:Originally posted by Skylon:Is Soyuz TMA-22 going to fly with the same crew? Or minus Dan Burbank?

Soyuz TMA-22 is scheduled to land after TMA-02M and before TMA-03M. That would seem to be an opportunity to bring one STS-135 crewman home earlier if Burbank didn't launch.

Robert Pearlman

Even if Burbank did not launch (and according to NASA, there's a chance he wouldn't) TMA-22 will be used to cycle ISS crew members rather than be used for the STS-135 astronauts.

Skylon

quote:Originally posted by Robert Pearlman:Even if Burbank did not launch (and according to NASA, there's a chance he wouldn't) TMA-22 will be used to cycle ISS crew members rather than be used for the STS-135 astronauts.

That makes a lot more sense Robert. I was playing the numbers and couldn't figure how Hurley would end up staying longer than Garan and Fossum on that timeline. It looks like based on the time line posted, it can work if TMA-22 goes up with the US seat vacant...Garan returns on that. Does Fossum then come back on a Soyuz TMA-M, launched with one cosmonaut?

Oh, and FYI: LM-12, Soyuz 4 and 5 did dock. Hence the very off-color "Help! We've been raped!" joke by one of Soyuz 5's crew when docking did occur.

LM-12

I must have been thinking about the Salyut flights that began a few years later.

Hart Sastrowardoyo

"More bad news, Rex: Not only are you staying on board ISS, but you're not eligible for the 100 Days patch, unless you want to stay another week or so."

LM-12

In a safe-haven situation, how would Atlantis be abandoned? Can the shuttle be undocked unmanned, or will it just be left in place docked to the ISS?

Jay Chladek

Atlantis would likely be undocked and deorbited to come down harmlessly over open ocean. It would essentially be the same plan in place to de-orbit a shuttle if another shuttle had to come up and bring the crew home since the docking port would need to be freed up.

A shuttle can't be powered down since it only has a finite load of consumables onboard for life support and the fuel cells (can the fuel cells be powered down? On Apollo they could not). Cut the fuel cells off and the cryo in the tanks is eventually going to bleed out anyway. The shuttle has to be undocked in a powered up state since something that massive can do serious damage to the ISS if you try to jettison it uncontrolled as a dead vehicle. Plus there would be no control of where it would come down at that point or when. The shuttle I believe can be placed into a low consumption standby mode to extend its supplies, but eventually it is going to need to be abandoned and de-orbited.

More than likely if the worst case scenario were to happen, Atlantis would remain docked as long as possible to use its supplies to extend the station. Fresh water could be transferred to the tanks onboard, additional cryo could be uploaded to the station loops and its fuel cells could provide supplemental power as well for certain uses. And it might get stripped of some minor parts possibly. But I don't believe that would last much longer than say three weeks at the most unless NASA were to come up with a fix for whatever stranded it in orbit and it could come home.

I have a question though. Do we know when Chris, Doug and Rex went to Russia to be fitted for their Sokol suits and seat liners? I figure Sandy's suit and liner likely are still in storage, but I've never heard news about when the other three went to Russia for their fittings. For that matter did Sandy have to go back for a second fitting to make sure her measurements hadn't changed much from her Expedition 18 flight?

LM-12

The NASA Human Spaceflight gallery has some photos taken in March 2011 of all four STS-135 crew members undergoing Sokol spacesuit fit checks in Moscow.

Hart Sastrowardoyo

What ever happened to the seat liners, Sokol suits and IVA jackets and pants made for the 135 crew? Recycled for other crewmembers? Downgraded for training purposes? Given to them?